Some sites don't allow incest, like i think if the game is on steam it can't have it. To counterract this, there is an incest patch that you load into the folder that changes the relationship to what it would actually be
That's not true, because on itch and Steam, there is also Grandma's House, Bad Memories, Sisterly Lust and Young Again and they either have incest patching or they have it in the storyline without the need of patching on Steam or itch, so that reason doesn't really fly. It's more likely a choice of the developer and not the site. I have in the past, just found the file that has the "Landlady" or "Landlord" relations and simply modified them with the correct terms of identifying the characters and ran it accordingly. Just sayin'.